A linearization method for commercial Hall-effect current transducers

The need for high-current transducers featuring wide-band and high-insulati on levels is becoming a more and more impelling need in the electric power network, as the current distortion increases due to the proliferation of no nlinear, time-variant loads. The closed-loop Hall-effect current transducer s show a good compromise between cost and metrological performance. On the other hand, they may introduce an unacceptable nonlinearity error when the dynamic range of the input current is a reduced portion of the dynamic rang e of the transducer and may show a large drift of their gain with temperatu re. The paper proposes a simple method for reduction of the nonlinearity er ror when the input signal is an unbiased sinewave and the automatic calibra tion of the gain. Experimental results are also reported, showing the metho d effectiveness.